Core Viewpoint - The Tianwen-2 mission represents China's first dual-target exploration of extraterrestrial small bodies, marking a significant advancement in deep space exploration. The mission aims to explore and sample asteroid 2016HO3 and conduct scientific investigations of main belt comet 311P over a complex 10-year mission period [1][3]. Mission Objectives - The Tianwen-2 mission has two primary objectives: to explore and collect samples from asteroid 2016HO3 and to conduct scientific exploration of main belt comet 311P [1][3]. Mission Complexity - The mission involves a complex flight process with approximately 13 flight stages, indicating high risk and difficulty [1][3]. - The spacecraft consists of a main probe and a return capsule, which will separate upon reaching Earth for re-entry [3]. Challenges in Exploration - The first major challenge is the trajectory design for reaching asteroid 2016HO3, which requires precise calculations due to the differing orbits of the Earth and the asteroid [8][10]. - The second challenge involves the sampling process at asteroid 2016HO3, where the characteristics of the asteroid's surface are largely unknown, necessitating a "fly, explore, and decide" strategy [5][7][12]. - The third challenge is the return of samples to Earth, which requires the spacecraft to withstand re-entry at speeds exceeding the second cosmic velocity, approximately 12 kilometers per second [15][17]. Mission Duration and Capabilities - The Tianwen-2 mission is expected to last about 10 years, with the first 2.5 years dedicated to the exploration and sampling of asteroid 2016HO3, followed by over 7 years of travel to comet 311P [18]. - The spacecraft must possess long-lasting capabilities to endure temperature variations and radiation over the mission duration [20]. - Enhanced communication capabilities are necessary due to the significant distance of asteroid 2016HO3, which is approximately 42 times the distance from the Earth to the Moon [22]. Autonomous Operations - The spacecraft is designed to operate autonomously, making decisions without constant ground control oversight, which is essential for long-duration deep space missions [24].